Commission-free brokerage Robinhood Markets Inc. on Thursday posted a $423 million net loss in the latest quarter, and its shares tumbled as much as 15 percent in after-hours trade even as revenue edged past analysts’ estimates. Robinhood reported a net loss of $423 million or $0.49 per share in the three months ended December. A year earlier, which was before its IPO, the company posted net income of $7 million or $0.01 per share. Shares of Robinhood sank as much as 15 percent to $9.98 in extended trading following results. The share price at its IPO in July last year was $38, and its record high in August was $85. Robinhood, in its third set of results as a public company, posted total revenue of $363 million for the fourth quarter ended Dec. 31, compared to $318 million a year earlier. Analysts on average had expected revenue of $362.14 million, …